Airplane stabilizer



April 24,- 1928.

C. J. SMITH AIRPLANE STABILIZER 2 Sheets-Sheet 1 Filed Des. 27. 1926 [NVENTOR flzarlasJJmz'Hz,

April :24 1928. 1,667,224

(1. J. SMITH AIRPLANE STABILIZER Filed Deb. 27. 1926 2 Sheets-Sheet 2 ail N bQ KN Patented Apr. 24, 1928.

UNITED STATES A RMAN-is I 1,667,224 OFFICE.

roan Moron comrANa r,

PATENT.

STABILIZER.

Application filed December 2'1, 1926. Serial 110. 157,341

The object of my invention is to provide an airplane stabilizer of simple, durable;

and inexpensive construction' Stilla fur ther objectof my invention is to provide in- 5 combination with. the movable elevator planes of an airplane, an adjustable stabilizer planewhereby the stabilizeiiplane may be moved to position relative to a horizontal plane to compensate ;for varying load conditions. Still a further object of my invention is to pivotally mount. one end of the stabilizer plane on a fuselage and toadjustably mount the other end so that the angle of the stabilize'r plane be varied relative to the axis the fuselage a Still a further object invention is to provide a means foradjusting the angle of the stabilizing-plane which may be extended toposition adjacent to the pilots U seat, so that the position of the stabilizer planemay be adjusted either before or dur- .ingfii ht. a Wit these and other objects in'view my invention consists in the arrangement, combinatio'nand oonstruction-. of the various parts of my improved device as. described in the specifications; claimed in the claim, and disclosed in the accompanying. drawings 30 in which:

Fig. 1. shows a somewhat diagrammatic elevation of an airplane fuselage having-my improved stabilizing plane installed thereon. Fig. 2 shows an enlarged elevation ofthe rear end of the fuselage shown in- Fig. 1.

Fig. 3 shows a top or plan view-of the deviceshowninFig.2. I

Fig. 4 shows a vertical central transverse detailed view of the adjusting device'for the stabilizing plane. 2

Fig. 5 show an shown in Fig. 4, partsbeingbroken away to better illustrate the construction, and Fig. ,6 shows a detail sectional view taken on the line 6-6 of Fig. 4).,

Referring to the accompanyingdrawings,"

I have used the reference numeral 10 to in dicate generally a fuselage having a tail post 11' upon which .arudder 12 is pivotally mounted. The usual -ver'tic'al stabilizing plane 13 and the tail skid-l4 arealso illush I w A horizontal stabilizing plane. 15 of ordinary construction is provlded adjacent to the rear end of the fuselage 10 and elevator elevation of the. device" planes 16 are pivotally connected. at 17 to the rearedge of the stabilizing plane 15. The stabilizingplane 15 is pivotally mounted atl8 on the fuselage 10 to swing on a transverse horizontal axis so that the rear end of the stabilizing plane 15 may be. swung up and down. housing 19 is securedto the tail post 11 in any suitable manner-as by bolts 20. This housing is of; substantially cylindrical shape and'is pro,- vided with a cylindrical-guardmember 21 4 which is telescopicallyimounted therein for vertical reciprocation. Rotatablybut non- --slidably mounted in the housing 19. and

gua-rd21 is a threaded sleeve 22 which is provided with gear teeth .at the lower end thereof. A worm 23 is rotatably but non slidably' mounted in a boss 24 on the housing 19 in' position to co-act with teeth on the bottom of-the. sleeve 22so that rotation of the Worm 23 on a. horizontal axis will impart rotation onthe' vertical axis to a sleeve '22. L

" A threaded shank 25 is mounted in the 'sleeve 22'to co-act with-,the -threads in the latter so that rotatioii'of the sleeve22 will cause ver'-' tical reciprocation gto the shank 25.

The upper end 'of. the shank 25- is provided with a clevis 26 in \which a link 27 is pivotally mounted. A similar clevis 28 is secured to the lower surface of the stabilizs5 ing plane '15 and is pi votally connected'to the second end of the link 27.

" From the construction-of the partsjust described it will be seen that rotation of the worm 24.- will reciprocatelthe shank" 25 to raise or lower the rear end; of the stabiliz-- ing plane 15 and to swing the latter on the pivot 18. An operating shaft 29 is'fixed in the worm 23 as by splines 30 and extends forwardialong the-fuselage to position antjacentlto the pilots; seat 36 where it is pro-' vided with an operating handle 31. At intervals along the length of the operating shaft 29 brackets 32 are secured to the side ofthe fuselage to support universal bear- 1 ing ;members" --33 in which the shaft 29 isjournalled so that warping or weaving oftheffusela will not interfere with the operation of t estabilizing plane adjusting means by the handle 31. 1.

Among the many advantages arising from athe use of my improved device, it should be I 'specially mentioned that the adjustment of the stabilizing plane-to meet load conditions reduces the wind resistance of the planeas 1 compared with the wind resistance which would be set up if the elevators alone were relied upon to compensate for different :weights of load. Furthenthe position of the stabilizer plane may' be adjusted before or during flight to correspond to the load carried so that thecontrols for the elevator 16 may always be normally inan intermediate position as distinguished from being toward either limit of their possible movement. This of course makes the operation of the airplane by the pilot easier as his controls will always tend to remain in a normal position-when in flight andthe full range of the movement of the elevators in compartment so that the position of the stabilizing plane may be varied during the flight. Some changes may be-made in the construction and arrangement of the various parts of my improveddevice Without departing from the spirit of my invention and it is my intention to cover by my. claim such changes as may be reasonably included within the scope thereof.

I claim as my invention:

In a device of the character described, a fuselage having a tail post at the rear end thereof, said fuselage having a horizontal longitudinal slot therethrough adjacent to said tail post, a stabilizer plane extended through said slot and pivotally mounted adjacent to its forward end within said slot, and means secured tosaid tail post and coactingavith said stabilizer plane to adjust that stabilizer plane about its pivot, the pivotal mounting and the adjusting evice both being disposed substantially within the lines of the fuselage whereby the said parts may not increase the wind resistance of the stabilizer plane. materially.

CHARLES J. SMITH. 

